HYBSIL

These small antelope centaurs look like a cross between a centaur and a pixie, brownie, or sprite.

In combat, they use short daggers, but their main weapons are their arrows. These cause 1-4 points of damage and are coated with a rare plant juice that causes sleep for 1-4 hours (save vs Poison at -4). 

Hybsils add +4 to all their saving throws because of their hearty constitutions.

They speak Hybsil, Elf, and Common. Bugbears, ogres, and especially gnolls are their mortal enemies. They are often on friendly terms with most 4-legged mammals, including antelopes, zebras, deer, and horses.

Hybsils live in large families or close-knit tribes in temperate or subtropical grasslands. They are seminomadic and may roam over vast areas or live an entire lifetime within a small thicket or grove. 

The tribal leader will be a witch doctor capable of either druid (60%) or magic-user (40%) spells and a casting ability of up to 7th level.